“…[13] We are interested in the preparation of carborane-fused borirane 1,2-BR-1,2-C 2 B 10 H 10 because of the very rich reaction chemistry of the corresponding three-membered metallacycles 1,2-[M]-1,2-C 2 B 10 H 10 (M = transition metals). [14,15] However,m any attempts to prepare 1,2-BR-1,2-C 2 B 10 H 10 through the reaction of Li 2 C 2 B 10 H 10 or 1,2-[M]-1,2-C 2 B 10 H 10 with 1equiv of RBX 2 failed. Unprecedentedly, irradiation of acarborane-fused azaborole 1 [16a] gave the first example of carbene-stabilized carborane-fused borirane 2 (Scheme 2).…”